From a3be098e5b03ddad89d22348f788f48b8b3bc812 Mon Sep 17 00:00:00 2001
From: pulipakaa24 <adipu@utexas.edu>
Date: Mon, 5 Jan 2026 20:36:21 -0600
Subject: [PATCH] rateLimit

---
 index.js | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/index.js b/index.js
index ab8de19..1af940c 100644
--- a/index.js
+++ b/index.js
@@ -11,10 +11,41 @@ const { initializeAgenda } = require('./agenda'); // Agenda setup (CHANGE THIS F
 const format = require('pg-format');
 const cronParser = require('cron-parser');
 const { ObjectId } = require('mongodb');
+const { RateLimiterMemory } = require('rate-limiter-flexible');
+
+// HTTP rate limiter: 5 requests per second per IP
+const httpRateLimiter = new RateLimiterMemory({
+  points: 5, 
+  duration: 1, 
+});
+
+// WebSocket connection rate limiter: 1 connection per second per IP
+const wsConnectionRateLimiter = new RateLimiterMemory({
+  points: 5,
+  duration: 1,
+});
+
+// WebSocket message rate limiter: 5 messages per second per socket
+const wsMessageRateLimiter = new RateLimiterMemory({
+  points: 5,
+  duration: 1,
+});
 
 const app = express();
 const port = 3000;
 app.use(json());
+
+// Rate limiting middleware for HTTP requests
+app.use(async (req, res, next) => {
+  const ip = req.ip || req.connection.remoteAddress;
+  try {
+    await httpRateLimiter.consume(ip);
+    next();
+  } catch (rejRes) {
+    res.status(429).json({ error: 'Too many requests' });
+  }
+});
+
 const pool = new Pool();
 const server = http.createServer(app);
 const io = socketIo(server, {
@@ -38,8 +69,39 @@ let agenda;
 const JWT_SECRET = process.env.JWT_SECRET;
 const TOKEN_EXPIRY = '5d';
 
+// Helper function to rate limit WebSocket messages
+async function rateLimitSocketMessage(socket, eventName) {
+  try {
+    await wsMessageRateLimiter.consume(socket.id);
+    return true;
+  } catch (rejRes) {
+    socket.emit('error', { 
+      type: 'error', 
+      code: 429, 
+      message: 'Too many messages. Please slow down.',
+      event: eventName 
+    });
+    return false;
+  }
+}
+
 io.on('connection', async (socket) => {
   console.log("periph connected");
+  
+  // Rate limit WebSocket connections by IP
+  const ip = socket.handshake.address;
+  try {
+    await wsConnectionRateLimiter.consume(ip);
+  } catch (rejRes) {
+    socket.emit('error', { 
+      type: 'error', 
+      code: 429, 
+      message: 'Too many connection attempts. Please wait.' 
+    });
+    socket.disconnect(true);
+    return;
+  }
+  
   const token = socket.handshake.auth.token ?? socket.handshake.headers['authorization']?.split(' ')[1];
   try {
     if (!token) throw new Error("no token!");
@@ -144,6 +206,8 @@ io.on('connection', async (socket) => {
 
   // Device reports its calibration status after connection
   socket.on('report_calib_status', async (data) => {
+    if (!await rateLimitSocketMessage(socket, 'report_calib_status')) return;
+    
     console.log(`Device reporting calibration status: ${socket.id}`);
     console.log(data);
     try {
@@ -165,6 +229,8 @@ io.on('connection', async (socket) => {
 
   // Device reports calibration error (motor stall, sensor failure, etc.)
   socket.on('device_calib_error', async (data) => {
+    if (!await rateLimitSocketMessage(socket, 'device_calib_error')) return;
+    
     console.log(`Device reporting calibration error: ${socket.id}`);
     console.log(data);
     try {
@@ -193,6 +259,8 @@ io.on('connection', async (socket) => {
 
   // Device acknowledges ready for stage 1 (tilt up)
   socket.on('calib_stage1_ready', async (data) => {
+    if (!await rateLimitSocketMessage(socket, 'calib_stage1_ready')) return;
+    
     console.log(`Device ready for stage 1 (tilt up): ${socket.id}`);
     console.log(data);
     try {
@@ -217,6 +285,8 @@ io.on('connection', async (socket) => {
 
   // Device acknowledges ready for stage 2 (tilt down)
   socket.on('calib_stage2_ready', async (data) => {
+    if (!await rateLimitSocketMessage(socket, 'calib_stage2_ready')) return;
+    
     console.log(`Device ready for stage 2 (tilt down): ${socket.id}`);
     console.log(data);
     try {
@@ -241,6 +311,8 @@ io.on('connection', async (socket) => {
 
   // User confirms stage 1 complete (tilt up done)
   socket.on('user_stage1_complete', async (data) => {
+    if (!await rateLimitSocketMessage(socket, 'user_stage1_complete')) return;
+    
     console.log(`User confirms stage 1 complete: ${socket.id}`);
     console.log(data);
     try {
@@ -269,6 +341,8 @@ io.on('connection', async (socket) => {
 
   // User confirms stage 2 complete (tilt down done)
   socket.on('user_stage2_complete', async (data) => {
+    if (!await rateLimitSocketMessage(socket, 'user_stage2_complete')) return;
+    
     console.log(`User confirms stage 2 complete: ${socket.id}`);
     console.log(data);
     try {
@@ -297,6 +371,8 @@ io.on('connection', async (socket) => {
 
   // Device acknowledges calibration complete
   socket.on('calib_done', async (data) => {
+    if (!await rateLimitSocketMessage(socket, 'calib_done')) return;
+    
     console.log(`Received 'calib_done' event from client ${socket.id}:`);
     console.log(data); 
     try {
@@ -323,6 +399,8 @@ io.on('connection', async (socket) => {
   });
 
   socket.on('pos_hit', async (data) => {
+    if (!await rateLimitSocketMessage(socket, 'pos_hit')) return;
+    
     console.log(`Received 'pos_hit' event from client ${socket.id}:`);
     console.log(data); 
     const dateTime = new Date();